1. Field of the Invention This invention relates generally to nonionizing radiation damage protection and more particularly to arrangements for shielding electronic and biological sensors and also electronic components from damaging microwave and millimeter wave radiation.
2. Statement of Related Art
Electronic sensors and electronic components are basic elements in radar systems, communication systems, guidance mechanisms, aircraft, and surveillance equipment deployed throughout the earth""s environment and also in space. Sensors and electronic components (especially VLSI circuits) are fragile and susceptible to disorientation or destruction by undesirable concentrated pulses of microwave or millimeter wave radiation. For example, a naked sensor could be irradiated with sufficient microwave energy from a traveling-wave tube to damage it or its supporting electronics. Presently transparent conductive coatings and meshes have been developed to shield electronic sensors and components. These coatings and meshes, however, have limited power handling capabilities. Improved devices, therefore, are needed to protect such components from undesired microwave or millimeter radiation that could be directed onto sensors or electronic components and damage them. Furthermore, these devices must be able to protect sensors over quite a broad bandwidth, preferably including both microwave and millimeter wave ranges. Any shielding arrangement, however, must be simple and not affect the normal functioning of the sensors or electronics.
Furthermore, since biological sensors, namely the human eye, could also be subjected to damaging microwave and millimeter wave radiation, shielding arrangements are also needed to protect these sensors.
It is therefore an object of the present invention to provide a sensor protection arrangement capable of shielding a sensor or electronic components from concentrated microwave and millimeter wave radiation.
It is a further object of the present invention to provide a sensor protection arrangement that is simple and easy to manufacture.
It is an advantage of the sensor protection arrangement that it can be retrofit into existing equipment.
In accordance with the foregoing objects, a sensor protection arrangement for protecting electronic and biological sensors and also sensitive electronic components from undesired microwave or millimeter wave radiation includes a reflective element having a major surface which in turn has a plurality of adjacent parallel ridges therein. Each ridge has an inclined face of a predetermined width which is substantially less than the wavelength of the undesired radiation. Consequently, these inclined ridge faces will tend to reflect only signals having wavelengths significantly less than any undesired microwave or millimeter wave radiation; while undesired signals with wavelengths significantly greater than the width of the inclined ridge faces will be reflected by the overall major surface of the reflective element. The inclined ridge faces are sloped so that desired incoming signals are directed toward a sensor. On the other hand, the front major surface is oriented with respect to the sensor so that undesired microwave or millimeter wave radiation will be directed by the overall front major surface away from the sensor (or other electronic components).
In another aspect, a sensor protection arrangement includes a honeycomb-like structure. The honeycomb-like structure is composed of a plurality of adjacent cells, each cell having a preselected cross-selectional area and length. The cross-sectional area and length of the cells are preselected to substantially attenuate signals with wavelengths greater than infrared wavelengths, namely undesired microwave or millimeter wave signals. However, signals in the infrared region pass through the cells substantially unattenuated to a sensor located behind the honeycomb device.